Relaciones entre densidades y biomasas de Salmo trutta fario y mediciones del mesohábitat en tramos trucheros de la Comunidad Valenciana
2007; Volume: 26; Issue: 1 Linguagem: Inglês
ISSN
2660-8537
AutoresJuan Diego Alcaraz-HernFrancisco Martnez-Capel,
Tópico(s)Freshwater macroinvertebrate diversity and ecology
ResumoRelationships between density and biomass of Salmo trutta fario and mesohabitat variables in trout streams of the Valencian region In the year 2003, populations of Salmo trutta fario were studied in the Valencian rivers. Habitat conditions were also studied along the successive hydro-morphological units in 300 m long reaches, along with geographic and water-quality variables. With the objective of relating density and biomass with the habitat, all the independent variables were used in a stepwise multiple regression analysis (for common trout density and relative biomass). Through a step-wise analysis, the most significant variables were chosen for each of the two multivariate models, showing all a low correlation coefficient, but with good significance (p < 0.10). The most relevant variables in both models were stream width (negative correlation) and percentage of cobbles (64-256 mm) in each mesohabitat. The water surface area, and mean and maximum depth did not appear in the final model, but their correlation with stream width was demonstrated. All these variables were included within the mesohabitat characteristics, having being discarded the rest that were not significant at the scale of the study.
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